The Menu Expanded module is a simple module designed to revert the changes made in #564886: Remove 'expanded' checkbox from menu item overview.
Even though there are certain circumstances where it is true that the "show as expanded" option will have no effect (shortcuts, toolbar, etc.) it is still IMHO a valuable item to have in the overview form. Many times, when setting up a menu, there may be dozens upon dozens of menu items that require marking this checkbox, and now with the new changes to _menu_overview_tree_form, it could take hundreds of clicks to edit menu items, then save, then edit the next, etc.
There may be a better way via the new AJAX system to accomplish this, and I will investigate that at another time, but for now, this module simply restores the "expanded" checkboxes on menu overview forms, making it quick and easy to set a single, or multiple items to expanded at one time.